Composite film

ABSTRACT

The present invention relates to a composite film. More particularly, the present invention relates to a composite compound film and composite compound multilayered film, comprising a metal, an alloy and/or an inorganic substance with an organic substance, which is excellent in decorative properties, protection and functionality. Methods applicable for forming such a composite compound film include the technique of evaporating a metal, an alloy, and/or an organic substance and an organic substance, simultaneously exciting the evaporated particles, and causing vapor-deposition in the state of ionized particles, neutral particles or radicals, and a method of sputtering, without excitation, etc. Further, a composite compound film which contains an organic substance can have an excellent color tone, and at the same time, reduces the amounts of high cost metals, alloys, or inorganic substances and provides a frictional coefficient lower than that of a film formed from a metal, an alloy or an inorganic substance alone. The film has a wear resistance which can be improved over that of a film comprising only the material of the composite film.

This is a divisional application of U.S. application, Ser. No.07/295,522, filed Jan. 10, 1989.

FIELD OF THE INVENTION

The present invention relates to a composite film. More particularly,the present invention relates to a composite film comprising a metal, analloy and/or an inorganic substance with an organic substance, whichcomposite film is excellent in decorative properties, forms a goodprotective film, etc.

PRIOR ART

It is common practice to form a vapor-deposited thin film of a metal, aninorganic material or an organic polymer on the surface of a substratecomprising a metal, glass, ceramics or plastics and to use the formedthin film as an insulating film, a reflecting film, an optical thin filma display element or an electronic device. The known processes for toachieve these purposes include vacuum vapor deposition, sputtering, ionplating, CVD, MOCVD, MBE, etc.

However, these conventional methods for forming a thin film stillpresent problems to be solved to achieve the desired properties andfunctions.

One of such problems is that the conventional films fail to possess thedesired excellence in color tone, corrosion resistance, adhesion wearresistance and other functional properties, particularly those films tobe used for watches and accessories. Furthermore, in order to form sucha film by a conventional method, it is necessary to prepare a layercomprising an expensive metal or an alloy thereof, thus resulting indifficulties in preparing a composite film excellent in decorativeproperties, protective properties, etc. and which can be manufactured ata low cost.

OBJECT OF THE INVENTION

The present invention proposes means to solve these problems by forminga composite film which is composed of a composite compound film, acomposite multilayered film or a composite compound multilayered film,comprising a metal, an alloy and/or an inorganic substance added theretowith an organic substance. That is to say, the present inventionprovides a composite film formed by vapor phase co-deposition of ametal, an alloy, and/or an inorganic substance with an organicsubstance. It also provides a composite multilayered film formed byvapor-depositing a thin film comprising a metal, an alloy and/or aninorganic substance and an organic polymer by a plasma exciting vaporphase deposition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial sectional view illustrating an embodiment of thecomposite compound film of the present invention, in which a goldcomposite compound film is vapor-deposited on a substrate having apreviously stacked TiN layer;

FIG. 2 is a partial sectional view illustrating an embodiment of thepresent invention, in which an undercoat is made on a TiN layer stackedon a substrate, and a gold composite compound film is formed on theundercoat;

FIG. 3 is a partial sectional view illustrating an embodiment of thepresent invention, in which a gold composite compound film is formed ona TiN layer stacked on a substrate, and a top coat is vapor-depositedthereon;

FIG. 4 is a partial sectional view illustrating a case where anundercoat is made on a TiN layer stacked on a substrate, gold compositecompound film being formed thereon, and a top coat is vapor-depositedfurther thereon;

FIG. 5 is a partial sectional view illustrating a case where atransparent conductive film is formed on the surface of the compositecompound multilayered film shown in FIG. 3;

FIG. 6 is a partial sectional view illustrating a case where a compositecompound film is formed on the composite compound multilayered filmshown in FIG. 3, and

FIG. 7 and 8 are sectional views illustrating typical composite films ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

As the metal or the alloy in the composite compound film of the presentinvention, gold and/or at least one metal selected from the groupconsisting of Cu, Al, Ni, Ag, Zn, Sn, Ta, V, Cr, Co, Pt, Pd, Ru, Rh, Ti,W, Mo, Ir, Cd, Sb, Hf, Ga, Si, Fe, Y, Ba, Ge, Zr, Nb, and In or an alloythereof is used. As the inorganic substance, TiN, TaN, ZrN, TaC, VNand/or C is employed.

Applicable organic substances include polycarbonates, polyacrylates,polysiloxanes, polyesters, polyolefins, and polyethylene.

Depending upon the material of the substrate on which the compositecompound film is to be formed, an undercoat comprising a metal, analloy, an inorganic substance and/or an organic substance may be formedon the surface of the substrate, and further a composite compound filmcan be stacked thereon and integrally therewith.

It is also possible to arrange a composite compound film as describedabove on the surface of a substrate, and stack a top coat comprising ameal, an alloy, an inorganic substance and/or an organic substancethereon and integrally therewith.

Futhermore, it is possible to form an undercoat comprising a metal, analloy, an inorganic substance and/or an organic substance on the surfaceof a substrate, stack a composite compound film thereon, and form a topcoat comprising a metal, an alloy, an inorganic substance and/or anorganic substance thereon and integrally therewith.

Methods applicable for forming such a composite compound film includethe technique of evaporating a metal, an alloy, and/or an inorganicsubstance and an organic substance, simultaneously exciting theevaporated particles, and causing vapor-deposition in the state ofionized particles, neutral particles or radicals, and the method ofsputtering, without excitation, etc. In terms of color tone and adheringstrength, it is desirable to integrally form the film in the excitedstate.

In the case, evaporated particles should preferably be excited in avacuum reactor by glow discharge and be plasma-ionized particles. Themethods applicable for plasma-ionization include ion-plating processsuch as the hollow cathode method and high-frequency excitation, andplasma CVD. For an organic substance, it is also possible to use themethod of polymer evaporation or introduction of monomer gas andvapor-depositing it through plasma polymerization.

For excitation, a light radiation such as laser beam could be applied.In adopting the ion-plating method, an inert gas such as argon could beintroduced into a vacuum reactor, for example, kept in vacuum at apressure of from 10⁻² to 10⁻⁵ Torr. Temperature of the substrate couldbe within the range of from the room temperature to about 400° C. Areactive gas such as oxygen, nitrogen, ammonia, hydrogen carbide,hydrogen sulfide, or hydrogen fluoride can be introduced for vapordeposition by reactive ion-plating. In this case, the gas pressureshould preferably be at least 10⁻⁴ Torr.

According to the present invention, as described above, it is possibleto achieve a composite compound film excellent in color tone, havingsatisfactory adhering strength and provided with such functionalproperties as dielectric properties, conductivity and light response.

In the present invention, the composite compound multilayered film is,for example, formed by vapor-depositing an organic polymer film on thesurface of substrate comprising a metal, an alloy, ceramics or plastics,and then sequentially forming a thin film comprising a metal, an alloyand/or inorganic substance, and an organic polymer layer, or formed byvapor-phase depositing a thin film comprising a metal, an alloy and/oran inorganic substance, then an organic polymer film, and subsequently,a thin film comprising a metal, an alloy and/or an inorganic substance.

The thin film comprising a metal, an alloy and/or an inorganic substancein the present invention is, for example, gold, a gold alloy or TiN, andnot limited to these examples, may be a metal, an alloy or an inorganicsubstance having desired color tone and gloss. Examples of the metal orthe alloy used in the present invention include such elements as gold,Cu, Al, Ni, Ag, Zn, Sn, Ta, V, Cr, Co, Pt, Pd, Ru, Rh, Ti, W, Mo, Ir,Cd, Sb, Hf, Ga, Si, Fe, Y, Ba, Ge, Zr, Nb and In, or an inorganicsubstance comprising a compound thereof such as TiN, TaN, ZrN, TaC, VNand/or C.

The organic polymer film in the present invention may be a thin filmcomprising a polymer such as a polycarbonate, a polyacrylate, apolysiloxane, a polyester, a polyolefin, or polyethylene. In this case,a dye compound or a pigment can be vapor-deposited for coloring.

There is no particular limitation for the substrate, which may be glass,a metal, an alloy, ceramics and plastics.

The thin film comprising a metal, an alloy and/or an inorganic substanceand the organic polymer film as listed above are formed byplasma-exciting particles produced through evaporation of the materialand vapor-depositing the resultant ionized particles, neutral particlesor radicals. It is also possible to form a thin film of a metal oralloy, not by excitation, but by sputtering, etc. However, with a viewto largely improving the color tone, the adhering strength and the andwear resistance of the composite multilayered film it is desirable tointegrally form it by plasma excitation.

The evaporated particles should preferably be excited by glow dischargein the vacuum reactor for plasma ionization. Means for plasma ionizationapplicable in this case include ion plating such as the hollow cathodemethod and the high-frequency excitation method, and plasma CVD. Whenforming the organic polymer film, plasma excitation can be applied byevaporating the polymer or introducing a monomer gas for vapordeposition. Laser beam excitation could be also applied.

When applying the ion plating method, an inert gas such as argon can beintroduced into a vacuum reactor kept in a vacuum at a pressure of, forexample, from 10⁻² to 10⁻⁵ Torr. The substrate temperature may be withinthe range of from room temperature to about 400° C. When forming aninorganic thin film, vapor deposition could be preferably carried out byion plating through introduction of a reactive gas such as oxygen,nitrogen, ammonia, hydrogen carbide, hydrogen sulfide, or hydrogenfluoride. In this case, the gas pressure should preferably be at least10⁻⁴ Torr.

According to the present invention, as described above, it is possibleto achieve a low-cost composite film excellent in color tone, having asatisfactory adhering strength, and provided with such functionalproperties as dielectric properties, conductivity and light response.

Now, concrete examples of the present invention will be described.Needless to say the present invention is not limited to these examples.

EXAMPLE 1

A composite film was formed by an ion plating apparatus based on thehigh-frequency excitation method. FIG. 1 illustrates this example. Astainless steel sheet was used as the substrate (1). The stainless steelsheet was bombarded by introducing argon gas under a condition of 5×10⁻³Torr, and then a TiN thin film (2) was vapor-deposited by reactive ionplating with nitrogen gas and evaporated Ti particles under a conditionof 8×10⁻⁴ Torr. A TiN thin film (2) having a thickness of 0.2 μm wasformed by a reaction for three minutes under conditions including adischarge power of 300 W and a substrate temperature of 100° C.

Then, under an argon pressure of 4×10⁻³ Torr, evaporated particles ofgold and polycarbonate were plasma-ionized to form a composite compoundfilm (3) on the substrate. As a result, a composite compound film (3)having a color tone equal to that of gold was obtained, with a wearresistance about twice as high as that available in the vapor depositionof gold on the substrate. As to adhering strength, no peeloff wasobserved in a bend test of 90°, and an excellent corrosion resistancewas shown.

EXAMPLE 2

In a manner similar to that in Example 1, a substrate (1) having atitanium nitride thin film (2) formed thereon was used, as shown in FIG.2, and under an argon pressure on 4×10⁻³ Torr, evaporated polycarbonateparticles were plasma-ionized. Thus, an undercoat (4) was formed byvapor-depositing a polymer film on the substrate.

Subsequently, a gold-chromium alloy (with a chromium content of 2%) wasevaporated together with polycarbonate to form a composite compound film(3) of polycarbonate and gold-chromium alloy with a thickness of about0.2 μm on the polycarbonate polymerization film.

The thus formed film has a color tone identical with that of agold-chromium alloy, with excellent adhesion, such that no separationwas observed in a 90° bend test, as well as high wear resistance andcorrosion resistance.

EXAMPLES 3

As in Example 1, a substrate (1) having a titanium nitride thin film (2)formed thereon was used as shown in FIG. 4 and under an argon pressureof 4×10⁻³ Torr, evaporated polycarbonate particles were plasma-ionized.Thus, a polymer film was vapor-deposited as the under coat (4) on thesubstrate.

Then, gold-chromium alloy (with a chromium content of 2%) was evaporatedtogether with polycarbonate to form a composite compound film (3) ofpolycarbonate and gold-chromium alloy having a thickness of about 0.2 μmon the polycarbonate polymer film.

Subsequently, evaporation of gold-chromium alloy was discontinued, andpolymer film comprising polycarbonate alone having a thickness of about0.2 μm was formed as the top coat (5) by vapor deposition on thecomposite film.

The thus formed film had color tone identical with that of agold-chromium alloy, with excellent adhesion, such that no separationwas observed in a 90° bend test, as well as high wear resistance andcorrosion resistance.

EXAMPLE 4

As shown in FIG. 3, a polycarbonate polymer film was vapor-deposited asthe top coat (5) under an argon pressure of 4 ×10⁻³ Torr on the surfaceof the composite compound film (3) obtained in Example 1. As a result, ahard transparent polymer film was obtained. This composite compoundmultilayered film had a color tone identical with that of gold, with agloss, and had an elegant appearance. This transparent polymer film wasexcellent in respect to the protection of the composite film, as well asin adhesion, wear resistance and corrosion resistance as in Example 1.

EXAMPLE 5

As shown in FIG. 5, a 0.3 μm-thick ITO (transparent conductivesubstance) film (6) was formed on the surface of the compositemultilayered film obtained in Example 4, with ITO as the evaporationsource under conditions including an oxygen gas pressure of 3×10⁻⁴ Torr,a discharge power of 300 W and a substrate temperature including thecomposite compound film (3) of Example 4 of 200° C. The thus obtainedcomposite compound multilayered film had a color tone of gold and agloss, resulting in an elegant appearance. Protection provided by thecomposite film was further improved, with excellent adhesion, wearresistance and corrosion resistance as in Example 1, and had a surfaceconductivity (resistance: 200Ω/□).

EXAMPLE 6

A composite multilayered film was formed by an ion plating apparatusbased on high-frequency excitation. As shown in FIG. 7, a stainlesssteel sheet was used as the substrate (11).

The stainless steel sheet was bombarded by introducing argon gas underthe pressure condition of up to a pressure of 5×10⁻⁵ Torr, and then, aTiN thin film (12) was vapor-deposited by reactive ion plating withnitrogen gas and evaporated Ti particles under a pressure of 8×10⁻⁴Torr. A 0.2 μm-thick TiN thin film (12) was formed through reaction forthree minutes under such condition, as to include a discharge power of300 W and a substrate temperature of 100° C.

A polymer film (13) was vapor-deposited by plasma-ionizing evaporatedparticles of polycarbonate under an argon pressure of 4×10⁻³ Torr. Then,a gold thin film (14) was formed through plasma-ionization of evaporatedgold particles under an argon pressure of 3×10⁻³ Torr.

This resulted in a multilayered film excellent in gold color tone. Allproperties such as color tone, adhering strength and wear resistancewere far superior to those available in the absence of an organicpolymer film, and wear resistance was about twices as high.

EXAMPLE 7

A polycarbonate polymer film was vapor-deposited under an argon pressureof 4×10⁻³ Torr on the surface of the composite multilayered filmobtained in Example 6. A hard transparent polymer film was obtained,with a glossy gold color tone giving an elegant appearance. The film wasexcellent in protection of the surface.

EXAMPLE 8

A transparent polyacrylate polymer layer and a thin gold film werevapor-deposited on a glass substrate as in Example 6. The gold filmshowed a satisfactory color tone and wear resistance was about twice ashigh as that available without vapor deposition of the polyacrylatepolymer film.

EXAMPLE 9

Polycarbonate polymer film (17) and an ITO (transparent conductivesubstance) film (18) were sequentially vapor-deposited on the surface ofthe multilayered film comprising a polyacrylate polymer film (15) and athin gold film (16) obtained in Example 6, as shown in FIG. 8. Theresultant composite multilayered film had a color tone of gold and asatisfactory surface conductivity (resistance: 200Ω/□).

The ITO thin film was formed, with ITO as the evaporation source, underconditions including an oxygen pressure of 3×10⁻⁴ Torr, a dischargepower of 300 W, and a substrate temperature of 30° C. It is a 0.3μm-thick transparent conductive film.

EXAMPLE 10

A composite compound film was formed by a high-frequency sputteringapparatus. A stainless steel sheet was used as the substrate. Afterpre-sputtering for about 15 minutes by introducing argon gas under apressure of 5×10⁻³ Torr, nitrogen gas was introduced under a pressure of5×10⁻⁴ Torr by the use of TiN as the target. Then, argon was introducedup to a pressure of 2×10⁻² Torr, and sputtering was conducted for twohours by applying a high-frequency power of 10 W/cm² to form a TiN filmhaving a thickness of about 0.5 μm. Subsequently, the target wasreplaced with Au (containing 1% Cr), and sputtering was conducted forabout 10 minutes with a high-frequency power of 2 W/cm² by introducingethylene (C₂ H₄) up to 1×10⁻⁴ Torr and adding argon gas up to 5×10⁻³Torr. A composite compound film comprising gold-chromium alloy andethylene was thus obtained, having a gold color tone, which is excellentboth in adhesion and corrosion resistance.

EXAMPLE 11

A composite compound multilayered film was formed by a high-frequencyion plating apparatus. A nickel-plated brass sheet was used as thesubstrate. After introducing argon gas up to 5×10⁻⁴ Torr, ionbombardment was conducted at a high-frequency power of 500 W and DCelectric field of -200 V for about 15 minutes. Then, titanium wasevaporated by an electron gun, by introducing argon gas up to 8×10⁻⁴Torr, under discharge conditions including a high-frequency power of 500W, a DC electric field of -200 V, to form a TiN film having a thicknessof about 1 μm in 30 minutes. Subsequently, the substrate was transferredto a high-frequency sputtering apparatus, in which sputtering wasconducted for about 10 minutes, with Au (containing 1% Cr) as thetarget, by introducing ethylene (C₂ H₄) up to 1×10⁻⁴ Torr and addingargon gas up to 5×10⁻³ Torr with a high-frequency power of 2 W/cm² toobtain a composite compound film comprising gold-chromium alloy andethylene. The resultant film had a gold color tone and was excellentboth in adhesion and as in corrosion resistance.

EXAMPLE 12

A composite compound film was formed by a high-frequency sputteringapparatus. A nickel-plated brass sheet was used as the substrate. Aftersputtering for about 15 minutes by introducing argon gas up to 5×10⁻³Torr, nitrogen gas of 5×10⁻⁴ Torr was introduced, with a TiN target, andthen, sputtering was carried out for two hours with a high-frequencypower of 10 W/cm² by introducing argon up to 2×10⁻² Torr to from a TiNfilm having a thickness of about 0.5 μm. Subsequently, the substrate wastransferred to an ion plating apparatus, in which gold (containing 1%Cr) was evaporated in a resistance-heating type boat under dischargewith a high-frequency power of 40 W by introducing ethylene gas to4×10⁻⁴ Torr, and a composite film comprising gold-chormium alloy andethylene having a thickness of about 1 μm was formed in 10 minutes. Theformed film was excellent in adhesion, wear resistance and corrosionresistance.

EXAMPLE 13

A composite compound film was formed by a high-frequency ionplating-apparatus. A glass plate (corning 7059) was used as thesubstrate. After ion bombardment conducted for 15 minutes underconditions including a high-frequency power of 300 W and a DC electricfield of -200 V by introducing argon gas up to 5×10⁻⁴ Torr, butadienegas was introduced up to 5×10⁻⁴ Torr, and a 1,000 Å composite compoundfilm was formed in about 10 minutes by evaporating germanium in aresistance-heating type boat under discharge of high-frequency power of50 W. This film showed negative resistance-temperature characteristicsand a specific resistance of from 10⁻⁴ to 10⁻⁵ Ω.cm.

EXAMPLE 14

A composite compound film was formed by the a high-frequency ion platingapparatus. A glass plate (corning 7059) was used as the substrate. Afterion bombardment conducted for 15 minutes under conditions including ahigh-frequency power of 300 W and a DC electric field of -200 V byintroducing argon gas up to 5×10⁻⁴ Torr, ethylene gas was introduced upto 5×10⁻⁴ Torr, and a 2,000 Å composite compound film was formed inabout 10 minutes by evaporating In (indium) in a resistance-heating typeheat under discharge of a high-frequency power of 50 W. This film wastransparent and showed negative resistance-temperature characteristics.

EXAMPLE 15

A composite compound film was formed by the a high-frequency ion platingapparatus. An aluminum plate was used as the substrate. After ionbombardment conducted for 15 minutes under conditions including ahigh-frequency power of 300 W and a DC electric field of -200 V byintroducing argon gas up to 5×10⁻⁴ Torr, ethylene gas was introduced upto 5×10⁻⁴ Torr, and a 200 Å composite compound film of Ni-Cr alloy andethylene was formed in about 10 minutes by evaporating an Ni-Cr alloy ina resistance-heating type boat under discharge of a high-frequency powerof 50 W. This film had a temperature coefficient of about ±10 ppm/deg,and a high specific resistance of 500 μΩ.cm, thus permitting use as ahigh-resistance element.

EFFECTS OF THE INVENTION

As described above in detail, the present invention provides thefollowing industrially useful effects by comprising forming a compositefilm on a substrate through vapor-phase deposition of metal, an alloyand/or an inorganic substance and an organic substance, andsimultaneously using as required a top coat, an undercoat, or both of atop coat and an undercoat;

1. It is possible to reduce the consumption of a metal, an alloy or aninorganic substance without changing the color tone of the metal, thealloy or the inorganic substance used.

2. The composite compound film having an organic substance can have africtional coefficient lower than that of a film formed from a metal, analloy or an inorganic substance alone, and wear resistance can beimproved over that of a film comprising only the material of thecomposite film.

3. In a film formed from a metal, an alloy or an inorganic substancealone, corrosion resistance may be affected by the occurrence ofpinholes. In the composite compound film, in contrast, corrosionresistance can be largely improved.

4. The composite film as applied to an article in direct touch withhuman skin gives less feeling of coldness than in touch with a metal, analloy or an inorganic substance.

Moreover the composite film can prevent an allergy to Ni ion, etc.

5. It is possible to provide the surface a composite film withconductivity, so that conductive films of various color tones can beprepared.

These merits are particularly effective when applying the presentinvention to an accessory, a watch, glasses and other articles ofutility, thus providing a very wide range of applications includingdisplay elements using various color tones as part of design thereof.

What is claimed is:
 1. A composite multilayered film structurecomprising a substrate having deposited thereon a composite compoundfilm formed by the vapor-phase exciting deposition on a substrate in anyorder of (1) a transparent organic polymer layer selected from the groupconsisting of a polycarbonate, a polyacrylate, a polysiloxane, apolyester, a polyolefin and/or polyethylene and (2) gold or its alloyand an inorganic substance selected from the groups consisting of TiN,TaN, ZrN, VN, TaC and C; or gold and its alloy and mixtures of TiN andC, TaN and C, ZrN and C, VN and C and TaC and C.
 2. A compositemultilayered film structure according to claim 1 wherein the substrateis first coated with an organic polymer layer as an undercoat, then withsaid layer (2) and then with said transparent organic polymer layer asan overcoat, both said organic polymer layers selected from the groupconsisting of a polycarbonate, a polyacrylate, a polysiloxane, apolyester, a polyolefin and/or polyethylene.
 3. A composite multilayeredfilm structure according to claim 1 wherein said composite multilayeredfilm contains an inorganic layer selected from the groups consisting ofTiN, TaN, ZrN, TaC, V and/or C as undercoat on the substrate, inaddition to said layers (1) and (2).
 4. A composite multilayered filmstructure according to claim 1 wherein the substrate is selected fromthe group consisting of glass, a metal, a ceramic and a plastic.
 5. Acomposite multilayered film structure according to claim 1 whichincludes two layers of layer (2) with an organic film selected from thegroup consisting of a polycarbonate, a polyacrylate, a polysiloxane, apolyester, a polyolefin and/or polyethylene interposed therebetween.